FFmpeg: libavfilter/transform.h File Reference

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libavfilter

Macros | Enumerations | Functions

transform.h File Reference

transform input video More...

#include <stdint.h>

Go to the source code of this file.

Macros

#define INTERPOLATE_DEFAULT INTERPOLATE_BILINEAR

#define INTERPOLATE_FAST INTERPOLATE_NEAREST

#define INTERPOLATE_BEST INTERPOLATE_BIQUADRATIC

#define FILL_DEFAULT FILL_ORIGINAL

Enumerations

enum InterpolateMethod { INTERPOLATE_NEAREST, INTERPOLATE_BILINEAR, INTERPOLATE_BIQUADRATIC, INTERPOLATE_COUNT }

enum FillMethod {
FILL_BLANK, FILL_ORIGINAL, FILL_CLAMP, FILL_MIRROR,
FILL_COUNT
}

Functions

void avfilter_get_matrix (float x_shift, float y_shift, float angle, float zoom, float *matrix)

Get an affine transformation matrix from a given translation, rotation, and zoom factor. More...

void avfilter_add_matrix (const float *m1, const float *m2, float *result)

Add two matrices together. More...

void avfilter_sub_matrix (const float *m1, const float *m2, float *result)

Subtract one matrix from another. More...

void avfilter_mul_matrix (const float *m1, float scalar, float *result)

Multiply a matrix by a scalar value. More...

int avfilter_transform (const uint8_t *src, uint8_t *dst, int src_stride, int dst_stride, int width, int height, const float *matrix, enum InterpolateMethod interpolate, enum FillMethod fill)

Do an affine transformation with the given interpolation method. More...

Detailed Description

transform input video

All matrices are defined as a single 9-item block of contiguous memory. For example, the identity matrix would be:

float *matrix = {1, 0, 0,
 0, 1, 0,
 0, 0, 1};

Definition in file transform.h.

Macro Definition Documentation

#define INTERPOLATE_DEFAULT INTERPOLATE_BILINEAR

Definition at line 47 of file transform.h.

#define INTERPOLATE_FAST INTERPOLATE_NEAREST

Definition at line 48 of file transform.h.

#define INTERPOLATE_BEST INTERPOLATE_BIQUADRATIC

Definition at line 49 of file transform.h.

#define FILL_DEFAULT FILL_ORIGINAL

Definition at line 60 of file transform.h.

Enumeration Type Documentation

enum InterpolateMethod

Enumerator
INTERPOLATE_NEAREST
INTERPOLATE_BILINEAR
INTERPOLATE_BIQUADRATIC
INTERPOLATE_COUNT

Definition at line 39 of file transform.h.

enum FillMethod

Enumerator
FILL_BLANK
FILL_ORIGINAL
FILL_CLAMP
FILL_MIRROR
FILL_COUNT

Definition at line 51 of file transform.h.

Function Documentation

void avfilter_get_matrix ( float x_shift,

float y_shift,

float angle,

float zoom,

float * matrix

)

Get an affine transformation matrix from a given translation, rotation, and zoom factor.

The matrix will look like:

[ zoom * cos(angle), -sin(angle), x_shift, sin(angle), zoom * cos(angle), y_shift, 0, 0, 1 ]

Parameters: x_shift horizontal translation

y_shift vertical translation

angle rotation in radians

zoom scale percent (1.0 = 100%)

matrix 9-item affine transformation matrix

Definition at line 106 of file transform.c.

Referenced by filter_frame().

void avfilter_add_matrix ( const float * m1,

const float * m2,

float * result

)

Add two matrices together.

result = m1 + m2.

Parameters: m1 9-item transformation matrix

m2 9-item transformation matrix

result 9-item transformation matrix

Definition at line 118 of file transform.c.

void avfilter_sub_matrix ( const float * m1,

const float * m2,

float * result

)

Subtract one matrix from another.

result = m1 - m2.

Parameters: m1 9-item transformation matrix

m2 9-item transformation matrix

result 9-item transformation matrix

Definition at line 125 of file transform.c.

void avfilter_mul_matrix ( const float * m1,

float scalar,

float * result

)

Multiply a matrix by a scalar value.

result = m1 * scalar.

Parameters: m1 9-item transformation matrix

scalar a number

result 9-item transformation matrix

Definition at line 132 of file transform.c.

int avfilter_transform ( const uint8_t * src,

uint8_t * dst,

int src_stride,

int dst_stride,

int width,

int height,

const float * matrix,

enum InterpolateMethod interpolate,

enum FillMethod fill

)

Do an affine transformation with the given interpolation method.

This multiplies each vector [x,y,1] by the matrix and then interpolates to get the final value.

Parameters: src source image

dst destination image

src_stride source image line size in bytes

dst_stride destination image line size in bytes

width image width in pixels

height image height in pixels

matrix 9-item affine transformation matrix

interpolate pixel interpolation method

fill edge fill method

Returns: negative on error

Definition at line 139 of file transform.c.

Referenced by deshake_transform_c().

Generated on Fri Jan 12 2018 01:46:13 for FFmpeg by doxygen 1.8.6